Furnace attachment



E. C. MASON. FURNACE ATTACHMENT. APPLICATION FILED JULY 15,1920.

1,394,634. 7 Patented Oct. 25, 1921.

.Madison, in the county of Dane,

@NETEQ STATEh PATENT @EFTQE.

EDWIN COLE MASON, OF MADISON; WISCONSIN".

FURNACE ATTACHMENT.

Application filed J'uly 15,

To all whom it may concern:

Be it known that I, EDWIN C. MASON, a citizen of the United States, residing at State of lVisconsin, have invented certain new and useful Improvements in Furnace Attachments; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and u'sethe same.

As is well known, soft coal is not asgood as hard coal for ordinary domestic use, first, because it does not keep a fire well, and second, because of its free liberation of smoke, soot and offensive gases. 7

It is an object of the present invention to facilitate the household use of soft or bituminous coal, as in the heating'of residences, by reducing the need for frequent stoking of the furnace, butmore especially by reducing the liberation of smoke or combustible gases into the chimney or into the residence.

These and other objects, hereinafter made clear, are attained by the use in the smoke box, or other equivalent passage of the furnace, of an auxiliary burner supplied with gas, oil, or the like, and serving to ignite combustible gases as they leave the fire box, thereby not only removing them as a nuisance, but also utilizing them as a source of heat. This auxiliary burner is also useful in controlling the draft through the smoke box, particularly at the time of replenishing coal in the fire box, and ithas other functions of advantage as hereinafter explained at length;

The accompanying. drawing is a sectional elevation, somewhat diagrammatic in character, .but intended to represent the present invention as applied to a hot air furnace such as is commonly used for'burning hard coal in the heatingof residences having eight to ten rooms.

7 In the embodiment illustrated, the furnace has a fire box. 5 with the usual ash pit 6, ash door? and hinged bottomdamperB-- The firebox 5can be fed with coal through the usual throat 9, normally closed by a feed door 10 having the usual sliding damper 11 for controlling the passage of air into the fire box above the bed of coal.

Products of combustion leave fire box 5 through an opening 15 and pass into a smoke box or dome 16 in which is the usual baflle Specification of Letters Patent. Patented Got. 25, TQZL 1920. Serial No. 396,369.

1 7. The products then pass through smoke pipe 18 to the chimney.

Surrounding the structure above described s a sheet metal jacket 19 having a cold air lnlet 20 and 'hot air pipes 25 leading to the various rooms of the residence.

The structure, as above described, may vary in many ways without departing from the spirit of the present invention.

As is usual in such furnaces, the smoke box 16 has a clean-out opening 12, but instead of the usual hinged door for closing this opening, I provide a plate 13 detachably bolted to-th'e front of the hot air jacket.

Pivotally mounted on plate 13, as by a rivet 14, is a door 24. Passing through plate 13, below door 24, is a burner tube 26, termi nating in a burner 28, which is positioned in the smoke box adjacent to the path of smoke coming from the fire box. The fluid fuel to be supplied to burner 28 may be natural or artificial gas or may be an oil, such as kerosene, or even a heavier oil, supplied at proper pressure from a suitable reservoir through pipe 27 and adequately controlled, as by a valve 30. V7 hen a liquid fuel, such 'as kerosene, is used, burner 28, which may be of the well known vaporizing type, can be lighted in the same way that a simple kerosene stove burner is lighted, and thereafter will burn with a hot blue flame as is well understood.

In the spring and fall of the year, when only enough heat is needed to take the chill from the rooms of the house, this burner 28 may be lighted and burned either continuously or for a short time, and the heat so generated will serve the needs of the household and obviate lighting a coal fire in fire box 5. But it is in very cold weather that the present invention has its greatest utility. The preferred mode of operation, and that r by which soft coal has been satisfactorily used by me in the heating of a small residence, is as follows Door 24 is swung on its rivet 14 to give access to burner 28. Valve 30 is opened to admit fluid fuel to this burner and the burner is lighted in usual manner. When the flame is going at full force with the lower draft door 8 closed and the swinging door 24 opened to the point at which the action of the flame is most vigorous, door 24 is closed and the feed door 10 of the furnace is immediately opened. The coal fire in the fire box 5 is now replenished with coal to the full capacity of the fire box, and the fuel door is then closed, but with the draft slide 11 so positioned that air can enter through the door. If it is found that the draft openings in this door 10 are inadequate for best use of the present invention, door 10 can be opened one-half to three-quarters of an inch to let in the desired abundance of air.

During the preliminary manipulations, the hot fluid fuel flame at burner 28 induces a strong draft over the new supply of coal in the fire box and upwardly through the smoke box to the chimney. And later on, the pull of the intense flame at burner 28, brings through the draft openings of feed door 10 suflicient oxygen to unite with the gases from the burning coal before smoke is formed to any considerable amount, so that light hydrocarbons and the like, distilling from the coal, have proper opportunity for ignition within the fire box. But any combustible gases passing out of fire box 5 through passage 15 come in intimate contact with the hot flame at burner 28, and are immediately ignited.

'After the coal has been well ignited, and when-the whole surface in the fire pot is covered with a bright, smokeless flame, the gas or oil supplied to burner 28 can be cut off at valve 30, and the air inlets and drafts may be adjusted to their normal positions. As a convenient way for shutting off the fluid fuel after the new charge of coal has been properly ignited, or, more strictly speaking, after the lapse of a predetermined time interval, I make use of a clock mechanism 29 having an arm 31 connected to a link 32 with a crank 33 on valve 30. These connections are indicated only diagrammatically in the drawing. But if desired, as in extremely cold weather, burner 28 may be kept in continuous operation so that the heat of its flame may supplement the heat from the burning coal.

lVith the arrangement above described, itis entirely feasible to burn soft soal for domestic purposes, as for heating a house with hot air, steam or hot water, and as I have found from experience there is no inconvenience either in the house or outside, because of the free lberation of gases when soft or bituminous coal is being coked. By thus burning gaseous products that would otherwise be a nuisance I am able to put large quantities of coal into the fire box at each stoking, and thus do not need to go to the furnace every few hours to keep the fire from going out. There is, of course, much economy in burning soft coal instead of hard coal for domestic heating purposes.

I claim 1. The combination with a household furnace, of a fluid fuel burner in the smoke box of said furnace for initiating a strong draft through said smoke box preparatory to stoking the furnace.

2. The combination with a household furnace in which soft coal is to be burned, of a liquid fuel burner in the smoke box of said furnace to strengthen the draft therethrough and ignite combustible gases distilled from the soft coal.

8. The combination with a household furnace having the usual fire box, smoke box, feed door and draft and clean-out openings, of a fuel supply pipe extending through the clean-out opening and having a fluid fuel burner within said smoke box, said burner being accessible for. lighting'preparatory to filling the fire box with soft coal.

at. The combination with a domestic hot air heater having the usual firebox surmounted by a smoke box, of a fluid fuel burner positioned where combustible gases enter said smoke box from said fire box, substantially as described.

5. In combination, a heater having a smoke box, and a fire box for solid fuel communicating with the smoke box by a restricted communication, and a fluid fuel burner arranged within the smoke box at the said communication and delivering in the same direction as the heated gases travel from the fire box to the smoke box, for strengthening the draft through the communication, and for burning combustible gases distilled from the fuel in the fire box.

6. In combination, a heater having a smoke box, and a fire box for solid fuel communicating withthe smoke box by a restricted communication, and a fluid fuel burner ar ranged within the smoke box at the'said communication and delivering in the same direction as the heated gases travel from the fire box to the smoke box, for strengthening the draft through the communication, and for burning combustible gases distilled from the fuel in the firebox, a valve controlling the supply of fluid fuel to the burner and clock work controlled mechanism for shutting off the valve at predetermined moments.

In testimony whereof I afiix my signature.

EDWIN COLE MASON. 

